/Engine/Source/Runtime/Engine/Classes/GameFramework/Actor.h
including the ones added via the BP editor (whichAActor.GetComponentsfails to do for CDOs).
template<typename TComponentClass, typename> static const TComponentClass * GetActorClassDefaultComponentByName ( const [TSubclassOf](API\Runtime\CoreUObject\Templates\TSubclassOf)< [AActor](API\Runtime\Engine\GameFramework\AActor) > & InActorClass, [FName](API\Runtime\Core\UObject\FName) InComponentName )